Molotov-Ribbentrop Pact

The Molotov-Ribbentrop Pact was a non-aggression pact signed between Nazi Germany and the Soviet Union in Moscow on 23 August 1939. The pact guaranteed that Germany and Russia would have peaceful relations and that they would have their own spheres of influence in Eastern Europe. The USSR was allowed to annex Estonia, Latvia, and Lithuania, and it also took over parts of Finland, all in 1940; Poland was equally partitioned between Germany and the Soviets. However, the Soviet annexation of Bukovina in 1940 went against the pact, and it was one of the causes of Operation Barbarossa - the Axis Powers invasion of the USSR - on 21 June 1941.